Wheels
Quality grades can be found where applicable on
the tire side wall between t read sho ulder and
maximum sect ion w idth
c::> page 235, fig . 204.
For example: Tr ead wear 200 , Tract ion AA, Tem
peratu re
A .
All passenger ca r tires must confo rm to Federal
Safety Req uiremen ts in add it ion to these grades.
Tread wear
The tread wear grade is a comparative rating
based on the wear rate of the tire when tested
unde r controlled conditions on a spec ified gov
ernment test course.
For examp le, a t ire graded 150 would wear one
and one half ( 1 1/2) t imes as well on the govern
ment course as a tire graded 100 .
The relat ive performance of t ires depends upon
the actua l conditions of their use, however, and
may depart significantly from the norm due to
variations i n driving hab its, service practices and
d iffe rences in road character istics and clima te.
Traction
The traction grades, from highest to lowest, are
AA, A , Band
C. Those grades represent the tire's
ab ility to stop on wet pavement as measu red u n
de r controlled cond it ions on spec ified govern
ment test su rfaces of asphalt and concrete. A tire
marked C may have poor traction performance
c::> &_ .
Temperature
The temperature grades are A (the highest), B,
a nd C, rep resent ing t he tire's res istance to the
genera tion of heat and its a bility to dis sipate
heat w hen tested unde r controlled cond itions on
a specified indoo r laboratory test whee l.
Sustained high temperature can cause the mate rial of the tire to degenerate and red uce tire life,
a nd excessive tempera ture can lead to sudden
tire failure
c::> &. .
The grade C co rresponds to a level of perform
ance wh ich a ll passenge r ca r tires m ust meet un
de r th e Federal Motor Vehicle Safety S tandard
No. 109. G rades Band A represent higher levels
252
of pe rformance on the laboratory test whee l than
the minimum required by law .
A WARNING -
The traction grade assigned to th is tire is
based on straight-ahead braking tract ion
tests, and does not include acce lerat ion, cor
nering, hyd roplaning or peak traction charac
teristics.
A WARNING
The temperature g rade for th is tire is estab
lished for a tire that is properly inf lated and
n ot ove rloaded. Excess ive speed, underi nfla
tion, o r ex cess ive lo adi ng, eithe r separately or
i n comb inat io n, can ca use heat bu ild up and
possible tire failure.
A WARNING
Tempe ratu re grades apply to ti res that are
properly inflated and not over or underinflat
ed.
Tire pressure monitoring system
(l) General notes
App lies to vehicl es: wi th tire p ress ure mo nito rin g system
-
Each tire, incl uding the spare (if provided),
sho uld be checked monthly when co ld and inflat
ed to the inflat ion pressure recommended by the
vehicle manufacturer on the vehicle placard or
tire inflat ion pressure label. (If your vehicle has
tires of a different s ize than the size indicated on
the ve hicle placard or t ire inflation pressu re la
bel, you should dete rm ine the p roper t ire infla
tion pressu re for those t ires).
As a n added safety feature, your ve hicle has been
equipped with a tire pressure mon itor ing system
( TP MS) that illum inates a low t ire pressure te ll-
ta le w hen o ne or mo re of yo ur ti res is sign ificant -
l y unde r-i nflated. According ly, w hen t he low t ire
pressure te lltale illuminates, you shou ld stop and
check yo ur tires as soon as possible, and inflate
them to the proper pressure . Dr iving on a signifi
cant ly under-inf lated tire causes the t ire to over
heat and can lead to tire failure. Under-inflation .,,.
